Police responding to the scene around 10 p.m. on Friday, July 17th found both 51-year-old Judith Williams of Walnut Creek and her 16-year-old son Adam Williams dead of gunshot wounds.

Autopsy results revealed the cause of death for Adam Williams as a gunshot wound to the chest and head. The cause of death for Judith Williams was determined to be a gunshot wound to the head.

"At this stage everything is pointing to a murder-suicide," said Captain Daniel Terry of the Office of the Sheriff Investigation Division. "We believe that Williams shot her son before turning the gun on herself."

Terry added that the handgun used in the shootings was registered to Judith Williams. Investigators searching her Walnut Creek home found a suicide note. Police also confirmed there was an ongoing custody battle.

Adam was a student and member of the cross country team at Las Lomas High School. A letter sent to students' parents said a memorial service has been planned for Adam Williams on Friday.

Investigators are not looking for any other suspects in this case but an investigation into the incident is ongoing. Anyone with any information on the case is asked to call the Investigation Division at (925) 313-2600.

Watch ABC7 News tonight at 6 for a full report on this tragic story from Cecilia Vega.